This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. COHORT is a coordinated research effort by Huntington Study Group research centers worldwide to prospectively collect data from consenting individuals who are affected by Huntington's disease (HD) and who are part of an HD family. The data from annual assessments will relate clinical characteristics (phenotypes) between families with genetic and environmental factors. The knowledge from these relationships will better inform us about the onset and progression of HD, help identify potential interventions for HD, and aid in planning research studies of experimental treatments aimed at slowing the onset of HD.